Large area synthesis of thin alumina films by laser ablation

Al2O3 has been ablated on commercially available 3″ silicon wafers at different distances between the target and the substrate and laser fluencies. ‘Amorphous’ Al2O3 (γ-alumina with grain size <20 nm) was grown by pulsed laser deposition at room temperature. The structure, the morphology, the profile and the composition of the produced films have been investigated. Fully oxidised thin films (thickness ≤5 μm) with high uniformity and smoothness were synthesised without additional oxygen gas during the ablation. The quality of the films was independent of the ablation fluency and of the distance between target and substrate.